Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: lguest: update commentry stop_machine: Remove deprecated stop_machine_run stop_machine: wean Xen off stop_machine_run virtio_balloon: fix towards_target when deflating balloon

Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: lguest: update commentry stop_machine: Remove deprecated stop_machine_run stop_machine: wean Xen off stop_machine_run virtio_balloon: fix towards_target when deflating balloon
Linus Torvalds
2 parents ffb4ba76a2 1dc3e3bcbf
Showing 5 changed files Side-by-side Diff
Documentation/lguest/lguest.c
drivers/lguest/lguest_device.c
drivers/virtio/virtio_balloon.c
drivers/xen/manage.c
include/linux/stop_machine.h
@@ -895,6 +895,9 @@
 	}
 }
  
+/* This is called when we no longer want to hear about Guest changes to a
+ * virtqueue.  This is more efficient in high-traffic cases, but it means we
+ * have to set a timer to check if any more changes have occurred. */
 static void block_vq(struct virtqueue *vq)
 {
 	struct itimerval itm;
@@ -939,6 +942,11 @@
 	if (!timeout && num)
 		block_vq(vq);
  
+	/* We never quite know how long should we wait before we check the
+	 * queue again for more packets.  We start at 500 microseconds, and if
+	 * we get fewer packets than last time, we assume we made the timeout
+	 * too small and increase it by 10 microseconds.  Otherwise, we drop it
+	 * by one microsecond every time.  It seems to work well enough. */
 	if (timeout) {
 		if (num < last_timeout_num)
 			timeout_usec += 10;
@@ -98,6 +98,10 @@
 	return features;
 }
  
+/* The virtio core takes the features the Host offers, and copies the
+ * ones supported by the driver into the vdev->features array.  Once
+ * that's all sorted out, this routine is called so we can tell the
+ * Host which features we understand and accept. */
 static void lg_finalize_features(struct virtio_device *vdev)
 {
 	unsigned int i, bits;
@@ -108,6 +112,10 @@
 	/* Give virtio_ring a chance to accept features. */
 	vring_transport_features(vdev);
  
+	/* The vdev->feature array is a Linux bitmask: this isn't the
+	 * same as a the simple array of bits used by lguest devices
+	 * for features.  So we do this slow, manual conversion which is
+	 * completely general. */
 	memset(out_features, 0, desc->feature_len);
 	bits = min_t(unsigned, desc->feature_len, sizeof(vdev->features)) * 8;
 	for (i = 0; i < bits; i++) {
@@ -158,7 +158,7 @@
 	vb->vdev->config->get(vb->vdev,
 			      offsetof(struct virtio_balloon_config, num_pages),
 			      &v, sizeof(v));
-	return v - vb->num_pages;
+	return (s64)v - vb->num_pages;
 }
  
 static void update_balloon_size(struct virtio_balloon *vb)
@@ -102,7 +102,7 @@
 	/* XXX use normal device tree? */
 	xenbus_suspend();
  
-	err = stop_machine_run(xen_suspend, &cancelled, 0);
+	err = stop_machine(xen_suspend, &cancelled, &cpumask_of_cpu(0));
 	if (err) {
 		printk(KERN_ERR "failed to start xen_suspend: %d\n", err);
 		goto out;
@@ -3,16 +3,13 @@
 /* "Bogolock": stop the entire machine, disable interrupts.  This is a
    very heavy lock, which is equivalent to grabbing every spinlock
    (and more).  So the "read" side to such a lock is anything which
-   diables preeempt. */
+   disables preeempt. */
 #include <linux/cpu.h>
 #include <linux/cpumask.h>
 #include <asm/system.h>
  
 #if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP)
  
-/* Deprecated, but useful for transition. */
-#define ALL_CPUS ~0U
-
 /**
  * stop_machine: freeze the machine on all CPUs and run this function
  * @fn: the function to run
@@ -50,19 +47,5 @@
 	return ret;
 }
 #endif /* CONFIG_SMP */
-
-static inline int __deprecated stop_machine_run(int (*fn)(void *), void *data,
-						unsigned int cpu)
-{
-	/* If they don't care which cpu fn runs on, just pick one. */
-	if (cpu == NR_CPUS)
-		return stop_machine(fn, data, NULL);
-	else if (cpu == ~0U)
-		return stop_machine(fn, data, &cpu_possible_map);
-	else {
-		cpumask_t cpus = cpumask_of_cpu(cpu);
-		return stop_machine(fn, data, &cpus);
-	}
-}
 #endif /* _LINUX_STOP_MACHINE */
...	...	@@ -895,6 +895,9 @@
895	895	}
896	896	}
897	897
	898	+/* This is called when we no longer want to hear about Guest changes to a
	899	+ * virtqueue. This is more efficient in high-traffic cases, but it means we
	900	+ * have to set a timer to check if any more changes have occurred. */
898	901	static void block_vq(struct virtqueue *vq)
899	902	{
900	903	struct itimerval itm;
...	...	@@ -939,6 +942,11 @@
939	942	if (!timeout && num)
940	943	block_vq(vq);
941	944
	945	+ /* We never quite know how long should we wait before we check the
	946	+ * queue again for more packets. We start at 500 microseconds, and if
	947	+ * we get fewer packets than last time, we assume we made the timeout
	948	+ * too small and increase it by 10 microseconds. Otherwise, we drop it
	949	+ * by one microsecond every time. It seems to work well enough. */
942	950	if (timeout) {
943	951	if (num < last_timeout_num)
944	952	timeout_usec += 10;
...	...	@@ -98,6 +98,10 @@
98	98	return features;
99	99	}
100	100
	101	+/* The virtio core takes the features the Host offers, and copies the
	102	+ * ones supported by the driver into the vdev->features array. Once
	103	+ * that's all sorted out, this routine is called so we can tell the
	104	+ * Host which features we understand and accept. */
101	105	static void lg_finalize_features(struct virtio_device *vdev)
102	106	{
103	107	unsigned int i, bits;
...	...	@@ -108,6 +112,10 @@
108	112	/* Give virtio_ring a chance to accept features. */
109	113	vring_transport_features(vdev);
110	114
	115	+ /* The vdev->feature array is a Linux bitmask: this isn't the
	116	+ * same as a the simple array of bits used by lguest devices
	117	+ * for features. So we do this slow, manual conversion which is
	118	+ * completely general. */
111	119	memset(out_features, 0, desc->feature_len);
112	120	bits = min_t(unsigned, desc->feature_len, sizeof(vdev->features)) * 8;
113	121	for (i = 0; i < bits; i++) {
...	...	@@ -158,7 +158,7 @@
158	158	vb->vdev->config->get(vb->vdev,
159	159	offsetof(struct virtio_balloon_config, num_pages),
160	160	&v, sizeof(v));
161		- return v - vb->num_pages;
	161	+ return (s64)v - vb->num_pages;
162	162	}
163	163
164	164	static void update_balloon_size(struct virtio_balloon *vb)
...	...	@@ -102,7 +102,7 @@
102	102	/* XXX use normal device tree? */
103	103	xenbus_suspend();
104	104
105		- err = stop_machine_run(xen_suspend, &cancelled, 0);
	105	+ err = stop_machine(xen_suspend, &cancelled, &cpumask_of_cpu(0));
106	106	if (err) {
107	107	printk(KERN_ERR "failed to start xen_suspend: %d\n", err);
108	108	goto out;
...	...	@@ -3,16 +3,13 @@
3	3	/* "Bogolock": stop the entire machine, disable interrupts. This is a
4	4	very heavy lock, which is equivalent to grabbing every spinlock
5	5	(and more). So the "read" side to such a lock is anything which
6		- diables preeempt. */
	6	+ disables preeempt. */
7	7	#include <linux/cpu.h>
8	8	#include <linux/cpumask.h>
9	9	#include <asm/system.h>
10	10
11	11	#if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP)
12	12
13		-/* Deprecated, but useful for transition. */
14		-#define ALL_CPUS ~0U
15		-
16	13	/**
17	14	* stop_machine: freeze the machine on all CPUs and run this function
18	15	* @fn: the function to run
...	...	@@ -50,19 +47,5 @@
50	47	return ret;
51	48	}
52	49	#endif /* CONFIG_SMP */
53		-
54		-static inline int __deprecated stop_machine_run(int (fn)(void ), void *data,
55		- unsigned int cpu)
56		-{
57		- /* If they don't care which cpu fn runs on, just pick one. */
58		- if (cpu == NR_CPUS)
59		- return stop_machine(fn, data, NULL);
60		- else if (cpu == ~0U)
61		- return stop_machine(fn, data, &cpu_possible_map);
62		- else {
63		- cpumask_t cpus = cpumask_of_cpu(cpu);
64		- return stop_machine(fn, data, &cpus);
65		- }
66		-}
67	50	#endif /* _LINUX_STOP_MACHINE */